If the SMTP server returns any AUTH dialects in its server options list then XMC will erroneously attempt to authenticate using the email address configured in SMTP options and fail authentication due to empty password (i.e. anonymous).
There are two workarounds:
- use of a username (email address) and password for a valid account on the SMTP server if the server support Basic Authentication (AUTH LOGIN).
- disable any additional AUTH dialects on the server such that the server options list does not contain any AUTH options; this will allow XMC to authentication anonymously.